I've recently encountered a very interesting problem. One of my cards (Asus RX470 Mining edition) started giving me 100% incorrect shares on ETH, while giving
correct shares on any of dual-mining algos at the same time. I've flashed original bios, lowered clocks, but the situation remained the same. I tried moving it to another AMD farm, with different everything (new risers, mobo, psu, os, driver version) but it gives 100% incorrect ETH shares (even with no dual mining). I then tried moving it to nvidia farm, where it was the only amd card - and it worked! The card was now giving correct ETH shares. But as soon as i added secong RX 470 to that farm - the first one started giving incorrect shares again
I've never encountered such a behaviour, any ideas would be greatly appreciated!